Migrate libtorch to GHA (#61774)
Summary:
Makes progress on https://github.com/pytorch/pytorch/issues/57686
Tested in https://github.com/pytorch/pytorch/pull/61775:
periodic 11.3 libtorch: https://github.com/pytorch/pytorch/pull/61775/checks?check_run_id=3088529584?check_suite_focus=True
10.2: https://github.com/pytorch/pytorch/pull/61775/checks?check_run_id=3089965441
11.1: https://github.com/pytorch/pytorch/pull/61775/checks?check_run_id=3089965697
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61774
Reviewed By: samestep
Differential Revision: D29745793
Pulled By: janeyx99
fbshipit-source-id: a17f561051b1e5eccf4918137a4b5df19308a716
